ELA
INTERIOR POINTS OF THE COMPLETELY POSITIVE CONE
∗MIRJAM D ¨UR† AND GEORG STILL‡
Abstract. A matrixAis called completely positive if it can be decomposed asA=BBT with an entrywise nonnegative matrixB. The set of all such matrices is a convex cone which plays a role in certain optimization problems. A characterization of the interior of this cone is provided.
Key words. Completely positive matrices, Copositive matrices, Cones of matrices.
AMS subject classifications.15A23, 15A48.
∗Received by the editors October 06, 2007. Accepted for publication January 20, 2008. Handling
Editor: Raphael Loewy.
†Technische Universit¨at Darmstadt, Department of Mathematics, Schloßgartenstr. 7, 64289
Darmstadt, Germany ([email protected]).
‡University of Twente, Department of Applied Mathematics, P.O.Box 217, 7500 AE Enschede,
The Netherlands ([email protected]). Electronic Journal of Linear Algebra ISSN 1081-3810 A publication of the International Linear Algebra Society Volume 17, pp. 48-53, February 2008
